Issue #2190313 by pfrenssen, Berdir, amateescu, ianthomas_uk: Add $EntityType::load() and loadMultiple() to simplify loading entities.

Issue #1807662 by sun, beejeebus, damiankloip, Wim Leers, Mixologic: Built-in APCu support in core (PHP 5.5 only).

Issue #2222719 by effulgentsia, tim.plunkett, xjm, dawehner: Use parameter matching via reflection for access checks instead of pulling variables from request attributes.

Issue #2266377 by dawehner, bkosborne, pwolanin: Speed up UrlGenerator a little by setting the 'external' option in the Url object  .

Issue #2267763 by pwolanin, tim.plunkett: Page titles with %placeholders are broken when used as breadcrumbs.

Issue #2266859 by tim.plunkett: Move the dependency calculation helper methods from ConfigEntityBase to generic traits.

Issue #2268439 by Gábor Hojtsy: String introspection backwards data typing is confusing / incorrect.

This reverts commit ecf2fa72.

This reverts commit c5c075df.

Issue #2229181 by pwolanin, Berdir, fago: MapItem::propertyDefinitions() claims it has a static value property, which is wrong.

Issue #2261369 by Berdir: Introduce a common config entity base class for all bundle config entity types.

Issue #2257835 by tim.plunkett, sun, Jalandhar: Move form submission logic out of FormBuilder into a new class.

Issue #2198713 by tstoeckler: Add a settings.php variable to allow to discover/enable test extensions at regular runtime.

Issue #2260321 by sun: Use Testing profile instead of Minimal profile in interactive installer tests by default.

Issue #2079863 by filijonka, mrsinguyen, fabricebernhard, Chernous_dn, YesCT: Remove Unused local variable from /core/lib/Drupal/Component Utility/Crypt.php  Transliteration/PHPTransliteration.php  Utility/UserAgent.php  Gettext/PoHeader.php.

Issue #2253977 by martin107, Mixologic: Use ConfigFactoryInterface to type hint ConfigFactory, Part II.

Issue #2265913 by pwolanin: LinkGenerator::generateFromUrl() fatal (uncaught exception) with external URL.

Issue #2116551 by cam8001, amateescu, swentel, Xano | webchick: Fix the UX of Entity Reference fields.

Issue #2259525 by alexpott: System.action.user_add_role_action.ROLE_ID does not match any config schema.

Issue #2228261 by beejeebus, kim.pepper, alexpott, Wim Leers | catch: Add a local, PhpStorage-based cache backend.

Issue #2257709 by znerol, Wim Leers: Remove the interdependence between the internal page cache and management of the Cache-Control header for external caches.

Issue #2216437 by Wim Leers: Entity labels are not in-place editable on 'full entity page' (prime example: node title).

Issue #2168809 by sun, damiankloip: Do not add the Guzzle HTTP client request subscriber outside of test environment.